regex matching for empty pk case

Author: A-Baji

datajoint/expression.py

@@ -126,10 +126,11 @@ def sorting_clauses(self):
             return ""
         clause = (
             ""
-            if not self.primary_key and order_by == ["KEY"]
-            else (
-                " ORDER BY "
-                + ", ".join(_flatten_attribute_list(self.primary_key, order_by))
+            if not self.primary_key
+            and all(
+                re.match(r"^\s*KEY(\s+[aA][Ss][Cc])?\s*$", a)
+                or re.match(r"^\s*KEY\s+[Dd][Ee][Ss][Cc]\s*$", a)
+                for a in self._top.order_by
             )
             else f" ORDER BY \
                 {', '.join(_flatten_attribute_list(self.primary_key, self._top.order_by))}"